66 8 lug c20 eaton swap

[handsomedevil66]

hey guys ,
not sure if there is another thread on this, so i thought i would ask
I have a 1966 chevy c20 with the eaton ho52 and want to swap the rear end
with something that will be more freeway friendly as this is my daily driver
what rear ends should i be looking for id like to stay away from 5 lug and keep the 8 lug if possible, ive talked to a rear end specialist and he told me the gears are not out there i would have to swap the rear end , any responses would be greatly appreciated , 350/350 power plant if that helps and i do plan on bagging the truck
thanks in advance for the help

[earl84]

I put in a 14 bolt from a 79 3/4 ton. Had to cut off the old spring perches and weld on new ones from Captainfab. I can't recall the WMS (wheel mounting surface) measurements, but it was close to stock, and I did not change that at all. I had two sets of 8 lug rims, one set from a 73-87 Chevy, the other from a Ford, but I can't remember the back spacing on either. Both are the same, though, and are stock rims from both of those trucks. The 14 bolt isn't exactly light, but mine had 3.08 gears and is fine on the highways around Denver. Not going to be smoking a lot of tires, but I also have a 454, so I can if I want to.

BTW, I highly recommend everything Captainfab makes/sells. I have the spring perches, the steering box adapter, and the brake booster adapter, and they all fit perfect, are high quality, reasonably priced, and Captainfab is a huge contributor on these forums, so I am happy to buy from him.

[handsomedevil66]

wow man thanks for the info im going to look for one and will definately hit up captainfab for the spring perches

[Chknlyps2]

Dana 60 is an option also, they were on some 67-72 Chevys and GMC's. I see them often on craigslist for a little cheaper than 14 bolts. They were even used on Ford vans in the 80's and probably later. Along with checking the gear ratio it would be a good idea to measure wheel mounting surface to wheel mounting surface as different applications were different.

[Captainfab]

A Dana 60 from a '68-'72 C 20 will be a direct bolt in and will have gears between 3.54 and 4.10. The 14 bolt was used from '73 on up. The Dana 60 was used extensively under F250's from the '60's up thru the 90's. Be aware that the Van versions of any differential are quite a bit wider than a pickup differential.

[handsomedevil66]

i found one from a 67? will that work? @captainfab

[gmcdeadhead]

i did the swap on my 66 c-20, it was a 14 bolt, 4:10 gears. i bought a 1987 chevy r30 single axel rolling chassis from a guy that was parting out the r30. i did the whole front end conversion , which he had already replaced all the front end parts , i got the steering box which he had already replaced and was practically new , did the hydro boost that came on the r30 , and i did the 14 bolt rear axle , got the whole thing for $600 buck , you cant beat that deal at all, i would look for a donor truck with half way decent parts and buy it that way. just my opinion, also bought all my conversion parts from captain fab, great price, and the parts fit great.